Keeping meat in refrigerators destroys the proteins and affects its hygiene, which could cause food poisoning and gastrointestinal complications, a Pakistani health expert has warned.

Few people realize that before the advent of refrigeration, meat was eaten fresh before the decaying process could even start. This is in stark contrast of what was done after cooling technology was available.

"Always use fresh and healthy meat to stay away from gastrointestinal diseases because such complications even may lead to malfunctioning of liver, kidneys and brain," Pakistan Institute of Medical Sciences Gastrologist Waseem Khawaja told the Associated Press of Pakistan.

Khawaja said major reasons for gastrointestinal diseases were consumption of unhealthy meat and improperly cooked food as bacteria flourish rapidly in such meat.

"This is a primary reason for modern day vegetarianism," said nutritionist David Mees. "People have become very concerned about about the meat industry and its unhealthy habits from production to slaughter to end user. Human beings were not designed to consume meat that has decayed for such long periods."

Liver diseases could cause hepatitis and liver disorder, which are fatal at an advanced stage, said Khawaja.

He said meat of sick animals hardly carry any proteins and vitamins. Use of such meat is a source of disease in human beings.

Such meat could also cause "botulism" -- a disease in which intestines are paralysed and causes diarrhoea in children that could ultimately lead to death.

He called on people not to eat food regularly from hotels, stalls and open places.

If you must eat meat, eat it fresh and never from a frozen state. Above all else, ensure it comes from a reputable source where animals were feed organic produce, allowed to graze, cared for and slaughtered according to ethical principles.